Elastic fluid power plant



Nov. 1, 1938. B. HOFFMANN ELASTIC FLUID POWER PLANT Filed Jan. 21, 1937 Patented Nov. 1, 1938 PATENT OFFICE ELASTIC FLUID POWER PLANT Bruno Hoffmann, Spandau, Germany, aasignor to'General Electric Company, a corporation of New York Application January 21, 1937, Serial No. 121,653 In Germany February 17, 1936 5 "Claims.

The present invention relates to elastic fluid power plants, especially to the arrangement of the auxiliaries of portable plants as are used on locomotives and aircraft.

The object of my invention is to provide an improved construction and arrangement of such power plants whereby they maybe readily put in operation and economically operated.

For a consideration of what I believe tov be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing. 1

The single figure of the drawing shows an elastic fluid power plant arrangement embodying my invention as may be used advantageously for operating aircraft.

The power plant comprises an elastic fluid engine in the form of a steam turbine I 0 for driving a propeller ll. Elastic fluid is supplied to the turbine Ill from a boiler l2 having a heatinclude in addition to the aforementioned condensate pump 11 boiler feed pumping means, in

the-present instance shown in the form of two- The auxiliaries further include a fuel pump 23 for conveying fuel from a tank 24 through a conduit 25 into a burner 26 forming a part of the boiler. Air for maintaining combustion is forced into the burner by means of a blower 21 having a discharge conduit 28 connected to the burner 26 As another auxiliary element for operating the power plant I have shown in the present instance a lubricating pump 29 having an inlet conduit 39 connected to an oil tank 31 and a discharge conduit 32 for supplying oil to various elements requiring, all under pressure during operation, such as bearings and servo motors (not shown).

In accordance with my invention, the auxiliar-- ies l1, I9, 29, 23, 21, and 29 are divided into two groups, one of which is driven from the shaft of the turbine Ill and the other operated by means of a gas turbine receiving combustion gases discharged from the boiler l2. More specifically,

the pumps 19 and 20 are directly driven from the shaft of the turbine Ill and the pump 11 is driven from said shaft through the intermediary of bevel gears 33. The pump 23 and the blower 21 have a shaft 34 to which is secured a gas turbine wheel 35 driven by gases discharged from the boiler.

The gases are directed to the wheel 35 by means of a nozzle diaphragm 36 and discharged from the wheel 35 into a flue 31. The shaft of the pump 29 is driven from the shaft 34 through bevel gears 38. Thus, the primary drive means for the auxiliaries comprise the turbine Ill and the gas turbine 35, 36. To facilitate starting of the plant, I provide a secondary drive means or motor shown in the form of a combustion engine 39 having a shaft 40 which may be 'coupled by means including a clutch 4| with the shaft of the pumps i 9, 20 and by means including a clutch 42 with the shaft 34 of the pump 23.

During starting, the clutch I2 is engaged to cause operation of the. pumps 23, 29 and of the blower 21 and thereby to supply fuel and air to the burner 26 and lubricant or actuating fluid to the bearings and servo motors. Thereafter, or if desired, simultaneously the clutch 4| is engaged to cause operation of the Dumps l1, I9, 20 and thereby to supply water to the boiler. As soon as the combustion has sufliciently developed to drive the gas turbine '35, 36. the clutch I2 is disengaged and finally upon operation of the turbine III the clutch ll is disengaged.

In a preferred embodiment, as shown in the drawing, the pumps l1, I9, 20 are driven from the main turbine or prime mover in order automatically to change the supply of water to the boiler in response to changes of load on the turbine.

The other auxiliaries are driven by the exhaust gas turbine because their operation depends primarily upon the load on the boiler. Furthermore, the other auxiliaries including the pump 23 and the blower 21 are to be operated at first during the heating of the boiler. It is also for this reason more advantageous if they are driven by an engine, in the present instance, the gas turbine, which is ready for operation before the turbine I0 is operated.

Summarizing, the auxiliaries for operating a by a gas turbine arranged to receive exhaust gases from the boiler, and the second group is arranged to be driven by a prime mover or other power agency independent of the gas turbine.

The two groups are started successively in their order aforementioned by means including a drive motor and clutches for separately'connecting the drive motor tothe groups. The drive motor is of relatively small size which is made possible by the separate starting of the two groups. Once the first group including the essential auxiliaries has been started and combustion gases are formed in the boiler and supplied to the gas turbine, the latter takes over the operation of the essential auxiliaries and the auxiliary drive motor becomes free to start the other auxiliaries.

What I claim as new and desire to secure by Letters Patent-of the United States is:

1. Elastic fluid power plant including the combination of a prime mover, a boiler for producing elastic fluid to actuate the prime mover, auxiliaries including pumping means for forcing operboiler connected to the condenser, auxiliaries including pumping means for forcing condensate from the condenser into the boiler and a fuel pump and a blower for forcing fuel and air into -the boiler, said auxiliaries forming two groups,

one group including the pumping means being' driven by the turbine, a gas turbine receiving combustion gases from the boiler for driving the fuel pump and the blower, and means for first starting the fuel pump and'the blower and thereafter'the pumping means, said means including a single drive motor and clutches for separately connecting the motor with each of said groups to permit successive starting of the groups by a relatively small drive motor.

3. Auxiliaries for operating a boiler comprising a first group of essential auxiliaries, a second group of other auxiliaries, drive means for normally operating the two groups, and means including a single drive motor for starting the first and then the second group, the" successive startinglof the two groups permitting the provision of a relatively small drive motor.

4. Auxiliaries for operating a boiler comprising a first group of essential auxiliaries including fuel and air supply means, a second group of other auxiliaries, drive means including a gas turbine for connection to such boiler for normally operating the first group, and means including a single drive motor and clutches for successively starting the groups in the order aforementioned.

- 5. Auxiliaries for operating a forced circu1a-, tion type boiler comprising a first group including fuel and air pumping means, a second group including pumping means for forcing operating fluid into the boiler, a gas turbine arranged to receive exhaust gases from such boiler normally to drive the first group, a power agency independent of the gas turbine normally to drive the second group, and means including a single drive motor for successively starting the two groups in the order aforementioned.

BRUNO HOFFMANN. 

